The University of Pennsylvania (Penn) Cancer Research Training Program is designed to identify and train the next generation of outstanding investigators focused on the problem of human cancer. The Program provides the protected time, resources, educational experience, mentorship and environment necessary to achieve this goal, as has been demonstrated throughout the past 25 consecutive years of funding. Traditionally focused on emerging physician-scientists training in medical and/or pediatric oncology, the Program has been highly successful in nurturing these young investigators to productive research careers in basic and clinical cancer research. To meet the increasing demands of our shared translational research mission and the growing size of our fellowship programs, as well as outstanding potential trainees in the ancillary medical, pediatric, surgical and pathology subspecialties, we now propose to increase the number of trainees supported by this program from six to eight. This is timely due to the number of highly qualified applicants to the program that we have not been able to support over the past five years. To support this increased number of trainees, we have carefully reviewed and revised our Steering Committee while maintaining the core leadership, we have newly appointed an external Advisory Committee, and have bolstered our faculty mentors to assure expertise in emerging areas such as immunotherapy, expand diversity and to assure that younger faculty engage in training through co- mentorship opportunities. Thus, the 44 faculty preceptors from the Abramson Cancer Center (ACC) at UPenn were selected from across the translational research spectrum to provide a rich group of potential mentors to all trainees. The modified Training Program will leverage the existing strengths that have been successful in training our physician-scientists, and we have now extensively enhanced our evaluation procedures, reformatted our annual retreat, and retooled our recruitment plans including a broad-based effort to enhance diversity, increasing the likelihood that our trainees will be future international leaders in cancer research